5l4k | pdb_00005l4k
The human 26S proteasome lid
Structural highlights
Function[PSMD1_HUMAN] Acts as a regulatory subunit of the 26 proteasome which is involved in the ATP-dependent degradation of ubiquitinated proteins. [PSMD7_HUMAN] Acts as a regulatory subunit of the 26S proteasome which is involved in the ATP-dependent degradation of ubiquitinated proteins. [PSMD8_HUMAN] Acts as a regulatory subunit of the 26S proteasome which is involved in the ATP-dependent degradation of ubiquitinated proteins. Necessary for activation of the CDC28 kinase. [PSMD3_HUMAN] Acts as a regulatory subunit of the 26 proteasome which is involved in the ATP-dependent degradation of ubiquitinated proteins. [PSD11_HUMAN] Component of the lid subcomplex of the 26S proteasome, a multiprotein complex involved in the ATP-dependent degradation of ubiquitinated proteins. In the complex, PSMD11 is required for proteasome assembly. Plays a key role in increased proteasome activity in embryonic stem cells (ESCs): its high expression in ESCs promotes enhanced assembly of the 26S proteasome, followed by higher proteasome activity.[1] [PSDE_HUMAN] Metalloprotease component of the 26S proteasome that specifically cleaves 'Lys-63'-linked polyubiquitin chains. The 26S proteasome is involved in the ATP-dependent degradation of ubiquitinated proteins. Plays a role in response to double-strand breaks (DSBs): acts as a regulator of non-homologous end joining (NHEJ) by cleaving 'Lys-63'-linked polyubiquitin, thereby promoting retention of JMJD2A/KDM4A on chromatin and restricting TP53BP1 accumulation. Also involved in homologous recombination repair by promoting RAD51 loading.[2] [3] [PSD13_HUMAN] Acts as a regulatory subunit of the 26S proteasome which is involved in the ATP-dependent degradation of ubiquitinated proteins. [PSD12_HUMAN] Acts as a regulatory subunit of the 26S proteasome which is involved in the ATP-dependent degradation of ubiquitinated proteins. [PSMD4_HUMAN] Binds and presumably selects ubiquitin-conjugates for destruction. Displays selectivity for longer polyubiquitin chains. Modulates intestinal fluid secretion. [DSS1_HUMAN] Subunit of the 26S proteasome which plays a role in ubiquitin-dependent proteolysis.[4] [PSMD6_HUMAN] Acts as a regulatory subunit of the 26S proteasome which is involved in the ATP-dependent degradation of ubiquitinated proteins. [PSMD2_HUMAN] Acts as a regulatory subunit of the 26 proteasome which is involved in the ATP-dependent degradation of ubiquitinated proteins. Binds to the intracellular domain of tumor necrosis factor type 1 receptor. The binding domain of TRAP1 and TRAP2 resides outside the death domain of TNFR1. Publication Abstract from PubMedProtein degradation in eukaryotic cells is performed by the Ubiquitin-Proteasome System (UPS). The 26S proteasome holocomplex consists of a core particle (CP) that proteolytically degrades polyubiquitylated proteins, and a regulatory particle (RP) containing the AAA-ATPase module. This module controls access to the proteolytic chamber inside the CP and is surrounded by non-ATPase subunits (Rpns) that recognize substrates and deubiquitylate them before unfolding and degradation. The architecture of the 26S holocomplex is highly conserved between yeast and humans. The structure of the human 26S holocomplex described here reveals previously unidentified features of the AAA-ATPase heterohexamer. One subunit, Rpt6, has ADP bound, whereas the other five have ATP in their binding pockets. Rpt6 is structurally distinct from the other five Rpt subunits, most notably in its pore loop region. For Rpns, the map reveals two main, previously undetected, features: the C terminus of Rpn3 protrudes into the mouth of the ATPase ring; and Rpn1 and Rpn2, the largest proteasome subunits, are linked by an extended connection. The structural features of the 26S proteasome observed in this study are likely to be important for coordinating the proteasomal subunits during substrate processing. Structure of the human 26S proteasome at a resolution of 3.9 A.,Schweitzer A, Aufderheide A, Rudack T, Beck F, Pfeifer G, Plitzko JM, Sakata E, Schulten K, Forster F, Baumeister W Proc Natl Acad Sci U S A. 2016 Jul 12;113(28):7816-21. doi:, 10.1073/pnas.1608050113. Epub 2016 Jun 24. PMID:27342858[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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